JP7252303B2 - Shock absorbing padding system with elastomeric subsurface structure - Google Patents

Description

This application claims priority to U.S. Provisional Patent Application No. 62/360,243, filed July 8, 2016, and is incorporated herein as fully set forth herein.

The present invention relates to systems for attenuating applied forces and absorbing impact energy, and more particularly, the present invention relates to elastomeric subsurface structures for attenuating applied forces and absorbing impact energy. and deformable structures, and more particularly, the present invention relates to structures and deformable structures in sports articles, such as stock pads, for dampening applied forces and absorbing impact energy.

Conventionally, several types of systems are used to dampen the recoil impact of shoulder-held firearms. Many such systems are known. Some use closed cell foam or vulcanized rubber chips that are consolidated together to provide a shock absorbing structure. The problems with most conventional gun pad constructions and the like are two-fold. Foams and most other conventional impact attenuating structures can actually stiffen and bottom out as the force applied to them increases. In most conventional systems, the force absorption mechanism begins with immediate displacement at the very surface of the pad.

Dense forms of rubber offer no protection against bottoming out, are relatively incompressible, and provide little recoil shock damping.
Recently, our patented advantages in the field of force damping have led to breakthroughs in many, if not all, aspects of the problem discussed above. In the area of materials composed of deformable cells with heights ranging from 25 to 75 mm, our patented technology has performed well. However, as the need for even smaller cells became apparent in thinner materials, our previous formulas for cell shape, dimensions, and height ratio between highly compressible and less compressible regions indicated that I It became clear that we could not obtain a shock absorbing material that could perform at a level comparable to our previous innovations. This is of particular interest in materials intended for use as recoil padding for firearms.

Conventional padding for use next to or attached to the body has techniques similar to those described above. It is common to use closed cell foams, gels or liquids, which may be rigid or more compressible depending on the application. All of these systems present some padding system drawbacks, many of which were discussed above.

A need exists for effective padding that is molded and shaped to the contours of the human body. Such impact attenuating padding may be attached to sports equipment, such as the buttstock of rifles, or the inside of helmets, or attached to the human body, for example, in knee, elbow, or shoulder pads, or in gloves. May be worn in any condition.

An impact attenuating pad for attachment to the abutment end of a firearm is disclosed. The pad has a bottom side that attaches to the stock of the firearm and a user side that is intended to rest against the user's body. For purposes of this disclosure, the bottom side will be referred to as the bottom and the user side will be referred to as the top of the pad. When viewed from above, the pad is generally oval in shape with curved sidewalls tapering to curved ends at each end.

Optionally, when viewed from the side, the pad tapers in thickness from one end to the other end. Advantageously, the pad has a total thickness at one end ranging from 0.8 to 1 inch (thickness shown is 0.998 inch). ) to 2.79-3.81 cm (1.1-1.5 inches) at the other end (thickness shown is 3.29 cm (1.295 inches)). good.

Contained within the pad is a series of frustum-shaped cylinders or posts, each containing a cavity. The central axis of each frustum cylinder stands perpendicular to the bottom of the pad. The upper portion of the cylinder is dome-shaped with a dome-shaped upper portion of the cylinder at the surface layer forming the user side of the pad.

Optionally, the cylinder walls are tapered both inside and outside such that the cross-section of each cylinder wall is narrow at the bottom of the cylinder and wide at the top. At a certain point, the inner wall of the cylinder is no longer linear and bends into the domed top of the cylinder. The cylindrical wall is narrower and more compressible at the bottom and wider and less compressible near the point where the inner wall bends into a dome.

The outer draft angle of the cylinder wall is the angle formed by the central axis of the frustum-shaped cylinder and a line in the vertical cross-section of the cylinder extending along the tapered outer wall of the cylinder. Preferably, this angle is greater than 5 degrees and less than 11 degrees (angle shown is 10 degrees). Similarly, the internal draft angle of a cylinder is the angle formed by the central axis of the cylinder and a line in a vertical cross-section of the cylinder extending along the tapered inner wall of the cylinder. Preferably, this angle is greater than 2 degrees and less than 5 degrees (angle shown is 4 degrees).

In one contemplated embodiment, the series of frustum-shaped cylinders increase in height from one end of the pad to the other. In this embodiment, the perimeter of the bottom of the cylinder is kept constant. At a certain point, the inner wall of the cylinder is no longer linear and begins to curve (bend into the domed top of the cylinder). Cross-sectional slices taken at this point are smaller for progressively higher heights due to the frustoconical shape of the cylinder.

In a particular version of this embodiment, the series of dome-shaped frustum cylinders gradually change in height. If each cylinder in the series is numbered from 1 to n, the height h of each cylinder in the series is approximately the formula h=0.0116n ² −0.0362n+0.53[+ or -0.04]
increases according to

The radius r of the circular cross-section of the cylinder truncated at the point where the inner wall ceases to be linear is then approximately the formula r=−0.0004n ² +0.0014n+0.20 [+or to −0.02]
becomes smaller according to

The thickness T _w of the cylindrical wall truncated at the point where the inner wall ceases to be linear is approximately the formula T _w =0.0013n ² −0.0037n+0.13 [to + or −0.02]
widens accordingly.

Embodiments of the elastic padding system are disclosed for use where the pad must conform to a relatively non-planar shape. The elastic padding system also includes a base structure that is a hollow column of a plurality of supporting elastic base structures, each column having a column wall forming a column, a first end and a closed second end. has an end of A post wall surrounds a central cavity, which extends from the first end of the post to the closed second end. The post wall also has a cross-sectional thickness that is narrower at the first end of the wall than at the closed second end of the wall. The portion of the wall that abuts the first end of the post is more collapsible with a thinner cross-section of the post wall than the less collapsible zone of the thicker cross-sectional area that abuts the second end of the wall. High zone.

In one embodiment, at least one of the pad surfaces is contoured to form a non-planar surface. The pad system has a cross-sectional pad thickness T that varies across the extent of the pad, and each central cavity defined by the post walls has a cross-sectional thickness T such that h varies across the extent of the pad. It has a height h at the central axis of the column within T. In addition, the surface layer having a cross-sectional thickness t extends beyond the closed end of each central cavity within a cross-sectional pad thickness T, whereby T=t+h, where The central cavity meets t at the central axis of each post. In this embodiment, the ratio of h:t is adjustable and may be in the range of greater than 4.0 to less than 6.0.

In some embodiments, the post wall is tapered to form a frustum-shaped post. The post wall has an inner surface and an outer surface, so in some embodiments the post wall is tapered on the inner and outer sides and has draft on both the inner and outer surfaces of the wall. ing. As the wall tapers, the cross-sectional thickness of the post wall increases from the first end of the post wall toward the closed end of the post wall by a percentage in the range of greater than 184% to less than 231%. may

Advantageously, in some embodiments, the post wall increases in thickness to meet and form a dome at the closed end.
In one embodiment, e.g., a preferred embodiment for a rifle butt tail pad, the height of each post extends from one end of the pad to contour to the part of the body that the rifle strikes when fired. It may increase towards the other. In this example, the post heights may vary according to the quadratic function represented above, where n refers to the post numbering from one side of the pad to the other, and Height h increases from one side of the pad to the other. Alternatively, the formula h=0.0116n ² −0.0362n+0.50 [to + or −0.04]
may apply. It is understood that slight variations of any of the expressed formulas and relationships are considered part of this disclosure to suit particular sports and physical uses of the disclosed pads.

Additional embodiments may advantageously be used in athletic padding used to attenuate impact stress in sports and recreational environments. Such padding may be attached to sports equipment, such as the buttstock of a rifle, or padding inside a helmet, or may be worn attached to the body, for example, with knee, elbow, or shoulder pads, or with gloves. good. Therefore, the same material can be used to contour to relatively non-planar shapes to provide impact attenuation between the human body and sports equipment, or when attached to the human body as padding in critical areas. Techniques may be formulated with different cell shapes, dimensions, and height ratios.

1 is a schematic diagram of a conventional closed-cell foam cushion in a static state; FIG. 1 is a schematic diagram of a conventional closed-cell foam cushion under load; FIG. FIG. 10 is a view of a disclosed embodiment of an elastomeric structure at rest; FIG. 3 is a view of a disclosed embodiment of an elastomeric structure under load; 1 is a cross-sectional front view of an embodiment of the disclosed pad, with certain elements enlarged for clarity; FIG. 1 is a cross-sectional front view of an embodiment of the disclosed pad, with certain elements enlarged for clarity; FIG. 1 is a cross-sectional front view of an embodiment of a disclosed pad; FIG. 4 is a graph of peak impact force versus drop height for selected embodiments;

Turning now to the drawings, the present invention is described in preferred embodiments with reference to the figures in which like numerals refer to like parts.
Multiple views, including cross-sectional views and other detailed views, of one embodiment of the disclosed gun pad are shown. A domed inner elastomeric cylinder with tapered walls is shown with a top or shoulder contacting surface.

References to "one embodiment" or "an embodiment" throughout this specification include at least one embodiment of the present invention that includes the particular feature, structure, or property described in connection with this embodiment. It means that Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Moreover, the specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

References to "column" throughout this specification refer to a tubular, shaft-like support structure, typically having a cylindrical or polygonal shaft and two shaft ends. Similarly, references to a "cylinder" throughout this specification refer to a tubular, shaft-like support structure that also has two shaft ends.

References to "column ends" throughout this specification refer to the set of points at which the column shaft is considered terminated. The column ends may be open or closed. Generally, columns referred to herein have a central axis, and column ends are defined by the column shafts ending in imaginary planes of intersection that are approximately perpendicular to the central axis of the column. be done. However, the closed post end may be dome-shaped, dimpled, or any other shape on the inner or outer surface of the post.

Generally, the pillars referred to herein are hollow pillars having a central cavity surrounded by a continuous curvilinear "pillar wall" defining the shaft or curved surface of the pillar. be. The column walls may be of uniform cross-sectional thickness throughout, or may be of adjustable cross-sectional thickness, e.g., relatively thick at one end of the column and relatively thin at the other end. It can be of any size.

The term "conical" throughout this specification refers to a shape generally described by the general higher geometric definition of cone. A cone is any three-dimensional shape formed by a set of line segments connecting a common point, or vertex, to all of a set of points on the base, the base being a plane containing no vertices. It should be noted that the base is not limited to a set of points forming a circle, the base may be any shape formed from any set of points. For example, cones with polygonal bases form pyramids, and cones with elliptical bases form elliptical cones.

Throughout this specification, reference to a "frustum" shape means that the sharp apex has been clipped, thereby leaving the base portion of the cone, and the cone is the number of points in the plane from the set of points forming the base of the cone. Refers to a cone shape that extends to the set and whose plane is roughly perpendicular to the central axis of the cone.

References to "outer draft" and "inner draft" throughout this specification refer to the following angles. Generally, the perimeter of the base of the cone is called the directrix, and the line segment between the directrix and the apex is the lateral generatrix. In the case of a cone shaped hollow pillar with the thickness of the pillar wall, there will be two cones, one inside and one forming the pillar. Both cones roughly share a central axis. One cone side forms the outer side of the column shaft and one cone side forms the inner side of the column shaft. The outer draft angle is the angle formed between the generatrix of the outer side surface and the common central axis. The internal draft angle is the angle formed between the generatrix of the internal side surface and the common central axis.

References to "bottoming out" throughout this specification refer to the point at which the cushioning material or structure has reached a state where further deformation in the direction of the force is relatively impractical.
1A and 1B are schematic diagrams of conventional closed-cell foam cushioning at rest and under load, respectively. In FIG. 1B, the foam cushion exhibits instability as the surface deforms under load, leading to potentially dangerous bonding due to surface deformation. Impact energy is absorbed by squashing the foam cells from top to bottom, causing the material to "harden" under load.

2A and 2B are views of a disclosed embodiment of an elastomeric structure at rest and under load, respectively. When the structure is impacted or loaded, the surface deformation is minimal, there is no tendency to bond, and the impact energy is transferred to the structure (cylindrical is shown) is absorbed by buckling or collapsing in a “controlled manner”. Therefore, as the collapsible structure continues to deform, the material becomes "softer" under load and the load is absorbed by the deformation of the relatively more resistant second zone, thus reducing the pad's structure. is less likely to “bottom out”.

FIG. 3 is a cross-sectional front view showing an embodiment of the disclosed pad 100 with an enlarged post or cylinder length for purposes of illustration. Pad 100 has a surface layer 110 . Surface layer 110 is supported by posts 120 with post walls 124 and central cavity 121 . Posts 120 may be of any existing suitable shape, although regular geometries are preferred, and cylindrical or frustoconical shapes are advantageous due to ease of manufacture, which shapes are used herein for all purposes. is discussed as a model for such pillars of (For ease of reference, the column is typically sometimes referred to as a cylinder, except for the specific discussion of the draft and other taper angles of the column 120 in the frustum column model.) The column wall 124 is advantageously There is a hollow central opening to the cavity 121 within the column 120 with a column end 127 that is a tubular end. The column wall 124 at the column end 127 has a width d. In one embodiment, the second end of the post is dome-shaped, with dome 128 forming the closed end of cavity 121 .

The column wall 124 has two zones, a first zone 105 in the region of the column end 127 and a second zone 103 in the region of the dome 128 . The second zone 103 is relatively crush resistant, whereas the first zone 105 is designed differently to not only undergo all of the workload compression, but also the initial overload crush or deformation. and is relatively much more compressible than the second zone 103 . A typical compression of the first zone 105 is accompanied by moderate deformation, indicated by a pair of dashed lines 109 as slight outward and inward bulging (relative to the central axis of the column). , because a compressive force (indicated by arrow 101) acts to vertically compress the elastomeric material in height and bulge the material away from the other boundaries of the wall. As the load increases, either due to increased load or due to impact, the first zone 105 deforms significantly in the direction indicated by arrow 104 in the manner indicated by the pair of dashed lines 107. It actually buckles or collapses. The material is essentially no longer compressed or expanded, instead being collapsed outward (relative to the central axis of the column) by the characteristic buckling collapse shown schematically.

The second zone 103 acts almost passively throughout the initial compression and deformation of the first zone 105 and during significant subsequent compression and deformation. Depending on the forces involved and the dimensions and properties of the rubber and posts, the second zone 103 may only exhibit a slight bulge represented schematically by the pair of dashed lines 102 . While this difference is intentional and other factors that are not yet fully understood may come into play, the apparent difference in compression effect and ultimate buckling collapse (first zone 105 only) is , due to the significant difference in geometry of zone 103 compared to zone 105 .

The first zone 105 begins as a relatively narrow cross-section at the post end 127 and increases in thickness, eventually increasing to a wall thickness sufficient to achieve the deformation effect described above. Roughly around this area of the pillar wall 124 is the virtual zone boundary 106 . On and above this imaginary zone boundary, any pre-existing compression or crushing will no longer be supported simply by the material properties due to the increased cross-sectional thickness. Above this imaginary boundary, the compressive force is applied to the second essentially through the first zone without bulging or other deformation effects in the zone. At such times, the relatively incompressible second zone 103 nevertheless "bottoms out" by absorbing the extraordinary impact energy remaining after being threaded toward the first zone 105. ” begins to act to prevent Given sufficient impact force, zone 105 will actually deform as well, absorbing more of the impact energy.

Although the schematic diagram of FIG. 3 shows that the first zone 105 gradually tapers into the second zone 103 upwards and merely crosses the imaginary boundary 106 between zones, other In embodiments, the demarcation is defined by increasing thickness upwards rather than in a gradual or tapered manner. For example, without limitation, the second zone 103 may have an abrupt thickness, perhaps by a thickened step on or around the boundary 106, such that the thickness increase is achieved abruptly rather than gradually. It can have thickness variations.

FIG. 4 is a cross-sectional front view of an embodiment of the disclosed pad 100 with an enlarged post or cylinder length for purposes of illustration. Post 120 has a width C at the closed end of the post, just below upper layer 110 . Cavity 121 has a top width w just before any dome 128 . In this alternative embodiment, the posts 120 have stiffening ribs 140 and/or links or bridges 130 leading to the underside of other posts or surface layers 110 (see also FIG. 3). In either case, the effect of the ribs 140 or links 130 is to make the relatively less collapsible zone 103 much stiffer, thereby reducing the effect of the second zone 103 (discussed in FIG. 3). It is to strengthen. At least one effect is that as long as the rib 140 or link 130 is joined to the post 120, the post width at that point will be significantly and effectively greater than under the rib or link or anywhere else on the post. . The ribs or links optionally have a taper that may optionally terminate in a rounded rib end or a flat end.

The column base 127 has a width d and the cavity opening 108 has a width W, where for a cylindrical or conical column closing a cylindrical or conical cavity, the area A of the column base is , the formula A=(π/4)*((W+2d) ² −W ² )
given by

FIG. 5 is a cross-sectional front view of an embodiment of the disclosed pad 100. FIG. This embodiment is a structure of suitable configuration for use, for example, in various types of competition and sports padding. For example, but not by way of limitation, the pad depicted by FIG. 5 functions as a gun pad or a rifle buttstock shoulder pad. This embodiment includes post 120, central cavity 121, post wall 124, and post end 127 discussed above with respect to FIG. This embodiment also includes a first relatively collapsible zone 105 and a second relatively less collapsible zone 103 of the column wall, all of which have shock absorbing properties as shown in FIG. was discussed.

In the embodiment of FIG. 5, post 120 is also frustum-shaped with tapered post wall 124 and optional dome 128, as discussed above with respect to FIG. Post wall 124 has inner and outer post wall drafts 123 and 125 . Preferably, the outer draft angle 125 is greater than 5 degrees and less than 11 degrees, and preferably the inner draft angle 123 is greater than 2 degrees and less than 5 degrees. For nominal column heights in the range of 0.4 to 0.7 inches, preferred draft angles are about 10 degrees for slope 125 and about 4 degrees for slope 123. .

In one contemplated embodiment, the surface layer 110 of the pad is contoured to comfortably fit the part of the body for which it is designed. For example, but not by way of limitation, a pad designed to be worn on the buttstock of a rifle may be contoured to fit over the shoulder, and the overall left side of the cross-sectional front view shown in FIG. The typical thickness T1 is about 1 inch (indicated by the pair of arrows T1 on the left side of pad 100), and the overall thickness T2 at the other end is about 3 inches. .30 cm (1.3 inches) (indicated by the pair of arrows T2 on the right side of pad 100).

The elastomeric structure of FIG. 5 also has a surface layer 110 with a substantially constant thickness t indicated by a pair of arrows t, and different post heights h illustrated by a pair of arrows h. . Advantageously, the array of elastomeric cylinders are graded in height to match the contours of surface layer 110 to facilitate the impact attenuation and cushioning properties of the pad for use in sports applications.

In the example of a rifle butt tail pad shown in FIG. 5, the series of frustum-shaped cylinders advantageously vary gradually in height from one end of the pad to the other. If a line is drawn across the column end 127, this gradual height will help maintain a constant thickness t of the surface layer while following the profile required by the structure. Become. In this embodiment, the perimeter of cylindrical opening 108 remains constant. At an imaginary perimeter 107 (indicated by dashed lines 107 ) within the shaft of column 120 , the inner wall of the cylinder ceases to be linear and begins to curve and bend to form a dome 128 . The cross-sectional slices cut at the perimeter 107 are smaller for progressively higher heights due to the frustoconical shape of the cylinder.

For example, the overall height T is increased from 2.54 cm to 3.3 cm (1 to 1.3 inches) and the constant cylindrical opening at the end opposite the dome has a diameter of 1.13 cm (0.3 inches). 445 inches), the continuous dome-shaped frustum cylinder is given by the following formula h = 0.0116n ² -0.0362n + 0.50 [to + or -0.02]
The height h (measured in inches) gradually changes accordingly, where each cylinder in the series is numbered from 1 to n.

Similarly, the diameter of a circular cross-section of a cylinder cut at the points where the inner wall ceases to be linear (indicated by dashed lines 107) narrows as the height of the cylinder increases, and the points at which the inner wall ceases to linear ), indicated by dashed line 107, increases as the height of the cylinder increases.

It is understood that in the case of an array of cylinders rather than a linear series, the height of the cylinders must be adjusted to match the contour of the surface layer 110 accordingly.
In FIG. 6, a graph of peak impact force vs. drop height curve is presented. This is different from the force versus displacement curves presented in previous disclosures. Such graphs provide more functionally applicable data regarding the design targeted performance of structures for absorbing impact shock.

For the data presented in the graph, peak impact force (Gmax) was measured for three different embodiments using Missile E according to ASTM procedure F355-10a. Gmax was plotted in inches as a function of drop height. The curves are obtained from data plotted using pad embodiments substantially as described herein.

The pad is generally made from an SBR/EPDM/natural rubber elastomeric material, advantageously with the following properties. That is, a Shore A durometer value of 40-70 (more particularly 40-50, and preferably about 44) measured at the surface of the mat, a modulus of about 0.5 MPa to about 4 MPa, and preferably about 0.5 MPa. 69 MPa.

A preferred substructure can be on a uniform grid or in a honeycomb configuration. Preferred substructures can be circular, elliptical, or multifaceted, made up of three to twenty or more sides. Preferred substructures may on the one hand have a shared wall configuration without links by elastomeric bridges between cylinders, or alternatively may be joined together by elastomeric links.

Regarding systems and components mentioned above but not otherwise specified or described in detail herein, the operation and specifications of such systems and components, and the manner in which they can be made and assembled All methods that can be obtained or used, whether they cooperate with each other or with other elements disclosed herein, to effectuate the purposes disclosed herein. is considered well within the knowledge of those skilled in the art. Accordingly, no specific attempt is made here to repeat what is generally known to those skilled in the art.

Impact and shock absorbing pads for sports equipment requiring padding, such as rifle butt tail pads, helmet huds, shoulder, knee and elbow pads, gloves, must prevent impact injuries and buffer repeated impact stresses. not.

The disclosed pads are adjusted to an ideal compliance level that studies have shown to maximize impact absorption performance. Optimized performance ensures stability and support while reducing pressure on specific body parts, reducing shock and maximizing fatigue reduction. Conventional compliant materials stiffen into compacts when compressed. The unique structure disclosed herein is actually hard to the touch, but softens as the applied force increases. The impact and shock absorbing pad is therefore adapted for use on or in many types of sports equipment.

In compliance with the regulations, the invention has been described in language more or less specific as to structural features. It should be understood, however, that the invention is not limited to the specific features shown, as the means and structures shown comprise preferred forms of practicing the invention. The invention is therefore claimed in any of its forms or modifications falling within the legal and fair scope of the appended claims properly interpreted in accordance with the doctrine of equivalents.

Claims (14)

An elastic pad system comprising at least one pad, said pad (100) having a surface,
Said pad (100) comprises a plurality of supporting elastic base structure hollow pillars (120), each pillar (120) of the plurality of pillars surrounding a central axis of the pillar and a central cavity (121) of the pillar. further comprising a wall (124) and a first end (127) and a second end of a post, said second end being closed and said cavity extending through said first end of said post extending from the portion (127) to the second end;
each post wall (124) of the plurality of posts (120) having a smaller cross-sectional thickness at the first end (127) of the respective post than at the closed second end; ,
at least one of the pad surfaces is contoured to be a non-planar surface;
the pad system having a cross-sectional pad thickness T that increases continuously from one side of the pad to the other;
Each central cavity defined by the post wall is spaced from the post within the cross-sectional pad thickness T such that h continuously increases from one side of the pad to the other. has a height h at the central axis of
A resilient pad system wherein a pad surface layer having a cross-sectional thickness t extends beyond said closed end of each central cavity within said cross-sectional pad thickness T, whereby T=t+h . the cross-sectional thickness of the post wall (124) increases from the first end of the post toward the closed end of the post by a percentage greater than 184% and less than 231%; 2. The resilient pad system of claim 1, wherein: The resilient pad system of claim 1, wherein the post wall (124) is tapered to form a frustum-shaped post. The resilient pad system of claim 1, wherein the post wall (124) increases in thickness to meet and form a dome (128) at the closed end of the post. The elastic pad system of claim 1, wherein the ratio of h:t is adjustable and is in the range of greater than 4.0 to less than 6.0. Where n refers to the numbering of the posts from one side of the pad to the other, the height h of the central cavity is given by the formula h=0.0116n ² -0.0362n+[0 up to .53+ or -0.04]
2. The resilient pad system of claim 1, increasing from one side of the pad to the other according to. The above [up to 0.53+ or -0.04] is 0.49, and the following formula h = 0.0116n ² -0.0362n + 0.49
7. The resilient pad system of claim 6, wherein: The resilient pad system of claim 2, wherein the post wall (124) is tapered to form a frustum-shaped post. The resilient pad system of claim 2, wherein the post wall (124) increases in thickness to meet and form a dome (128) at the closed end of the post. 3. The elastic pad system of claim 2, wherein the ratio of h:t is adjustable and is in the range of greater than 4.0 to less than 6.0. Where n refers to the numbering of the posts from one side of the pad to the other, the height h of the central cavity is given by the formula h=0.0116n ² -0.0362n+[0 up to .53+ or -0.04]
3. The resilient pad system of claim 2, increasing from one side of the pad to the other according to. The above [up to 0.53+ or -0.04] is 0.49, and the following formula h = 0.0116n ² -0.0362n + 0.49
12. The resilient pad system of claim 11, wherein: Where n refers to the numbering of the posts from one side of the pad to the other, the height h of the central cavity is given by the formula h=0.0116n ² -0.0362n+[0 up to .53+ or -0.04]
6. The resilient pad system of claim 5, increasing from one side of the pad to the other according to. The above [up to 0.53+ or -0.04] is 0.49, and the following formula h = 0.0116n ² -0.0362n + 0.49
14. The resilient pad system of claim 13, wherein:

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